Dentinal hypersensitivity is defined as acute, localized tooth pain in response to physical stimulation as by thermal (hot or cold), osmotic, tactile, and/or a combination of thermal, osmotic and tactile stimulation of the exposed dentin.
It is known to the art that potassium salts are effective in the treatment of dentinal hypersensitivity. For example, the prior art discloses that toothpastes containing potassium salts, such as potassium nitrate, desensitize the teeth after tooth brushing for several weeks. It is reported that an elevation in the extracellular potassium concentration in the vicinity of pulpal nerves underlying sensitive dentin is responsible for the therapeutic desensitizing effect of topically applied oral products which contain potassium nitrate. Due to passive diffusion of potassium ion into and out of the open dentine tubules, repeated application of the active ingredient is necessary to build up the necessary concentration in the vicinity of the pulpal nerves.
In addition to treating dental hypersensitivity, it is desirable to provide dentifrice to control dental plaque. Plaque adheres tenaciously at the points of irregularity or discontinuity, e.g., on rough calculus surfaces, at the gum line and the like. Besides being unsightly, plaque is implicated in the occurrence of gingivitis and other forms of periodontal disease.
A wide variety of antibacterial agents have been suggested in the art to retard plaque formation and the oral infections and dental disease associated with plaque formation. For example, halogenated hydroxydiphenyl ether compounds such as triclosan are well known to the art for their antibacterial activity and have been used in oral compositions to counter plaque formation by bacterial accumulation in the oral cavity. The effectiveness of the antibacterial agent is dependent upon its delivery to and uptake by teeth and soft tissue areas of the gums.
There is therefore a need in the art to provide means whereby the delivery to and uptake by dental tissue of antibacterial compounds contained in oral compositions containing potassium ions to provide therapeutic efficacy of the antibacterial agent with a desensitizing dentifrice.